U.S. patent application number 14/574711 was filed with the patent office on 2015-07-09 for three-dimensional shaped article manufacturing method, three-dimensional shaped article manufacturing apparatus, ink set, and three-dimensional shaped article.
The applicant listed for this patent is SEIKO EPSON CORPORATION. Invention is credited to Eiji OKAMOTO.
Application Number | 20150190965 14/574711 |
Document ID | / |
Family ID | 53494532 |
Filed Date | 2015-07-09 |
United States Patent
Application |
20150190965 |
Kind Code |
A1 |
OKAMOTO; Eiji |
July 9, 2015 |
THREE-DIMENSIONAL SHAPED ARTICLE MANUFACTURING METHOD,
THREE-DIMENSIONAL SHAPED ARTICLE MANUFACTURING APPARATUS, INK SET,
AND THREE-DIMENSIONAL SHAPED ARTICLE
Abstract
A three-dimensional shaped article manufacturing method with
which a three-dimensional shaped article having a glossy texture
can be manufactured stably and efficiently is provided. A
three-dimensional shaped article manufacturing method for
manufacturing a three-dimensional shaped article by laminating
layers formed by discharging and curing inks including a curable
resin, the method including: applying a substantive section-forming
ink to a region that forms the three-dimensional shaped article,
and applying a sacrificial layer-forming ink for forming a
sacrificial layer to a region that is adjacent to a region that
forms an outermost layer of the three-dimensional shaped article
and on a surface side of the outermost layer, a viscoelasticity of
the sacrificial layer-forming ink during curing of the substantive
section-forming ink being not less than a viscoelasticity of the
substantive section-forming ink during curing of the substantive
section-forming ink.
Inventors: |
OKAMOTO; Eiji; (Matsumoto,
JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SEIKO EPSON CORPORATION |
Tokyo |
|
JP |
|
|
Family ID: |
53494532 |
Appl. No.: |
14/574711 |
Filed: |
December 18, 2014 |
Current U.S.
Class: |
428/195.1 ;
264/401; 425/132; 522/64 |
Current CPC
Class: |
Y10T 428/24802 20150115;
C09D 11/40 20130101; B29K 2105/0005 20130101; B33Y 70/00 20141201;
C09D 11/101 20130101; B29C 64/264 20170801; B29L 2009/00 20130101;
B29C 64/40 20170801; B29C 33/448 20130101; B29C 64/209 20170801;
B29C 64/295 20170801; B29K 2105/0058 20130101; B29K 2105/0032
20130101; B33Y 30/00 20141201; B29C 64/112 20170801; B29K 2033/26
20130101; C09D 11/322 20130101; B33Y 10/00 20141201; B29C 64/393
20170801 |
International
Class: |
B29C 67/00 20060101
B29C067/00; C09D 11/107 20060101 C09D011/107 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 9, 2014 |
JP |
2014-002681 |
Claims
1. A three-dimensional shaped article manufacturing method for
manufacturing a three-dimensional shaped article by laminating
layers formed by discharging and curing inks including a curable
resin, the method comprising: applying a substantive
section-forming ink to a region that forms the three-dimensional
shaped article; and applying a sacrificial layer-forming ink for
forming a sacrificial layer to a region that is adjacent to a
region that forms an outermost layer of the three-dimensional
shaped article and on a surface side of the outermost layer, a
viscoelasticity of the sacrificial layer-forming ink during curing
of the substantive section-forming ink being not less than a
viscoelasticity of the substantive section-forming ink during
curing of the substantive section-forming ink.
2. The three-dimensional shaped article manufacturing method as set
forth in claim 1, further comprising removing the sacrificial layer
from a provisional molded article obtained by curing the
substantive section-forming ink and the sacrificial layer-forming
ink.
3. The three-dimensional shaped article manufacturing method as set
forth in claim 1, wherein the sacrificial layer-forming ink
includes 2-(2-vinyloxyethoxy)ethyl(meth)acrylate.
4. The three-dimensional shaped article manufacturing method as set
forth in claim 3, wherein the sacrificial layer-forming ink
includes polyethylene glycol di(meth)acrylate, in addition to
2-(2-vinyloxyethoxy)ethyl(meth)acrylate.
5. The three-dimensional shaped article manufacturing method as set
forth in claim 1, wherein the substantive section-forming ink
includes one or more species selected from the group consisting of
2-(2-vinyloxyethoxy)ethyl(meth)acrylate, polyether-based aliphatic
urethane(meth)acrylate oligomer,
2-hydroxy-3-phenoxypropyl(meth)acrylate, and
4-hydroxybutyl(meth)acrylate.
6. The three-dimensional shaped article manufacturing method as set
forth in claim 1, wherein the substantive section-forming ink and
the sacrificial layer-forming ink both include
bis(2,4,6-trimethylbenzoyl)-phenyl phosphineoxide and/or
2,4,6-trimethylbenzoyl-diphenyl-phosphineoxide as a polymerization
initiator.
7. The three-dimensional shaped article manufacturing method as set
forth in claim 1, wherein a color ink containing a coloring agent
and, in addition thereto, a colorless ink not containing a coloring
agent are used as the substantive section-forming ink, the
colorless ink being used upon formation of the region that forms
the outermost layer, and the color ink being used upon formation of
a region that is inside therefrom.
8. The three-dimensional shaped article manufacturing method as set
forth in claim 1, wherein a chromatic color ink and a white ink are
used as a color ink containing a coloring agent, the white ink
being used upon formation of a region inside of a region formed
using the chromatic color ink.
9. The three-dimensional shaped article manufacturing method as set
forth in claim 1, wherein a plurality of different types of the
sacrificial layer-forming ink are used.
10. The three-dimensional shaped article manufacturing method as
set forth in claim 1, wherein the sacrificial layer-forming ink is
selectively applied only to a part of the region that is adjacent
to the region that forms the outermost layer of the
three-dimensional shaped article and on the surface side of the
outermost layer.
11. A three-dimensional shaped article manufacturing apparatus for
manufacturing a three-dimensional shaped article by laminating
layers formed by discharging and curing inks including a curable
resin, the apparatus comprising: a first discharge unit configured
to discharge a substantive section-forming ink to a region that
forms the three-dimensional shaped article; a second discharge unit
configured to discharge a sacrificial layer-forming ink for forming
a sacrificial layer to a region that is adjacent to a region that
forms an outermost layer of the three-dimensional shaped article
and on a surface side of the outermost layer; and a curing unit
configured to cure the substantive section-forming ink and the
sacrificial layer-forming ink, a viscoelasticity of the sacrificial
layer-forming ink during curing of the substantive section-forming
ink being not less than a viscoelasticity of the substantive
section-forming ink during curing of the substantive
section-forming ink.
12. An ink set used for manufacturing a three-dimensional shaped
article by laminating layers formed by discharging and curing inks
including a curable resin, the ink set comprising: a substantive
section-forming ink applied to a region that forms the
three-dimensional shaped article; and a sacrificial layer-forming
ink applied to a region that is adjacent to a region that forms an
outermost layer of the three-dimensional shaped article and on a
surface side of the outermost layer, a viscoelasticity of the
sacrificial layer-forming ink during curing of the substantive
section-forming ink being not less than a viscoelasticity of the
substantive section-forming ink during curing of the substantive
section-forming ink.
13. A three-dimensional shaped article manufactured using the
three-dimensional shaped article manufacturing method as set forth
in claim 1.
14. A three-dimensional shaped article manufactured using the
three-dimensional shaped article manufacturing apparatus as set
forth in claim 11.
15. A three-dimensional shaped article manufactured using the ink
set as set forth in claim 12.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to Japanese Patent
Application No. 2014-002681 filed on Jan. 9, 2014. The entire
disclosure of Japanese Patent Application No. 2014-002681 is hereby
incorporated herein by reference.
BACKGROUND
[0002] 1. Technical Field
[0003] The present invention relates to a three-dimensional shaped
article manufacturing method, a three-dimensional shaped article
manufacturing apparatus, an ink set, and a three-dimensional shaped
article.
[0004] 2. Related Art
[0005] Conventionally known is a method of forming a
three-dimensional shaped article on the basis of a model of a
three-dimensional object generated with, for example,
three-dimensional computer-aided design (CAD) software or the
like.
[0006] A lamination method is one known method of forming a
three-dimensional shaped article. A lamination method generally
comprises forming the three-dimensional shaped article by dividing
the model of the three-dimensional object into a large number of
two-dimensional cross-sectional layers and thereafter sequentially
laminating cross-sectional members corresponding to each of the
two-dimensional cross-sectional layers while the cross-sectional
members are also being sequentially shaped.
[0007] The lamination method makes it possible to immediately form
any model of a three-dimensional shaped article intended to be
shaped, and is free of such needs as creating a mold prior to the
shaping, and therefore makes it possible to form a
three-dimensional shaped article both quickly and inexpensively.
Also, the three-dimensional shaped article is formed by laminating
the cross-sectional members, which are thin and plate-shaped, one
layer at a time, and therefore it is possible to form even a
complex object having, for example, an internal structure as an
integrated shaped article without dividing the object into a
plurality of components.
[0008] One known form of such a lamination method is a technique
for shaping the three-dimensional shaped article while also fixing
a powder with a binding solution (see JP-A-2001-150556 (patent
document 1), for example). With the technique of such description,
the formation of each of the layers entails imparting color to the
three-dimensional shaped article by discharging an ink comprising a
coloring agent onto a location corresponding to an outer surface
side of the three-dimensional shaped article.
[0009] However, with the conventional methods, an unintended
wrinkling is generated irregularly, and it is difficult to render a
glossy texture.
SUMMARY
[0010] Aspects of the present invention are to provide a
three-dimensional shaped article manufacturing method with which a
three-dimensional shaped article having a glossy texture can be
manufactured stably and efficiently, to provide a three-dimensional
shaped article manufacturing apparatus with which a
three-dimensional shaped article having a glossy texture can be
manufactured stably and efficiently, to provide an ink set that can
be used in order to stably and efficiently manufacture a
three-dimensional shaped article having a glossy texture, and to
provide a three-dimensional shaped article having a glossy
texture.
[0011] Such aspects are achieved by the present invention described
below.
[0012] A three-dimensional shaped article manufacturing method of
the present invention is a method for manufacturing a
three-dimensional shaped article by laminating layers formed by
discharging and curing inks including a curable resin, the method
including: applying a substantive section-forming ink to a region
that forms the three-dimensional shaped article; and applying a
sacrificial layer-forming ink for forming a sacrificial layer to a
region that is adjacent to a region that forms an outermost layer
of the three-dimensional shaped article and on a surface side of
the outermost layer, a viscoelasticity of the sacrificial
layer-forming ink during curing of the substantive section-forming
ink being not less than a viscoelasticity of the substantive
section-forming ink during curing of the substantive
section-forming ink.
[0013] This makes it possible to provide a three-dimensional shaped
article manufacturing method by which a three-dimensional shaped
article having a glossy texture can be manufactured stably and
efficiently.
[0014] The three-dimensional shaped article manufacturing method of
the present invention, preferably, includes removing the
sacrificial layer from a provisional molded article obtained by
curing the substantive section-forming ink and the sacrificial
layer-forming ink.
[0015] This makes it possible for an observer to more suitably view
a surface state where an unintended wrinkling has not been
generated, because the substantive section is exposed in the
three-dimensional shaped article that is ultimately obtained. For
this reason, the effects of the present invention are more
prominently exhibited.
[0016] In the three-dimensional shaped article manufacturing method
of the present invention, preferably, the sacrificial layer-forming
ink includes 2-(2-vinyloxyethoxy)ethyl(meth)acrylate.
[0017] This makes it possible to cure the sacrificial layer-forming
ink at a more appropriate speed of curing, causes the glossy outer
appearance to be more reliably obtained in the three-dimensional
shaped article, and makes it possible to provide the
three-dimensional shaped article with particularly excellent
productivity.
[0018] In the three-dimensional shaped article manufacturing method
of the present invention, preferably, the sacrificial layer-forming
ink includes polyethylene glycol di(meth)acrylate, in addition to
2-(2-vinyloxyethoxy)ethyl(meth)acrylate.
[0019] This makes it possible to cure the sacrificial layer-forming
ink at an even more appropriate speed of curing, causes the glossy
outer appearance to be more reliably obtained in the
three-dimensional shaped article, and makes it possible to provide
the three-dimensional shaped article with particularly excellent
productivity.
[0020] In the three-dimensional shaped article manufacturing method
of the present invention, preferably, the substantive
section-forming ink includes one or more species selected from the
group consisting of 2-(2-vinyloxyethoxy)ethyl(meth)acrylate,
polyether-based aliphatic urethane(meth)acrylate oligomer,
2-hydroxy-3-phenoxypropyl(meth)acrylate, and
4-hydroxybutyl(meth)acrylate.
[0021] This makes it possible to cure the substantive
section-forming ink at a more appropriate speed of curing, causes
the glossy outer appearance to be more reliably obtained in the
three-dimensional shaped article, and makes it possible to provide
the three-dimensional shaped article with particularly excellent
productivity.
[0022] In the three-dimensional shaped article manufacturing method
of the present invention, preferably, the substantive
section-forming ink and the sacrificial layer-forming ink both
include bis(2,4,6-trimethylbenzoyl)-phenyl phosphineoxide and/or
2,4,6-trimethylbenzoyl-diphenyl-phosphineoxide as a polymerization
initiator.
[0023] This makes it possible to cure the substantive
section-forming ink and the sacrificial layer-forming ink at a more
appropriate speed of curing, causes the glossy outer appearance to
be more reliably obtained in the three-dimensional shaped article,
and makes it possible to provide the three-dimensional shaped
article with particularly excellent productivity.
[0024] In the three-dimensional shaped article manufacturing method
of the present invention, preferably, a color ink containing a
coloring agent and, in addition thereto, a colorless ink not
containing a coloring agent are used as the substantive
section-forming ink, the colorless ink being used upon formation of
the region that forms the outermost layer, and the color ink being
used upon formation of a region that is inside therefrom.
[0025] This makes it possible to more suitably render the glossy
texture.
[0026] In the three-dimensional shaped article manufacturing method
of the present invention, preferably, a chromatic color ink and a
white ink are used as a color ink containing a coloring agent, the
white ink being used upon formation of a region inside of a region
formed using the chromatic color ink.
[0027] This makes it possible for the region (a first region) to
which the white ink is applied to exhibit masking, and makes it
possible to further raise the chroma of the three-dimensional
shaped article.
[0028] In the three-dimensional shaped article manufacturing method
of the present invention, preferably, a plurality of different
types of the sacrificial layer-forming ink are used.
[0029] This makes it possible, for example, for the
three-dimensional shaped article that is ultimately obtained to
have a plurality of regions at which the degree of glossiness is
different. As a result, it becomes possible to render a more
complex outer appearance, and the three-dimensional shaped article
can be given a particularly excellent aesthetic appearance
(aesthetics), luxuriousness, and the like.
[0030] In the three-dimensional shaped article manufacturing method
of the present invention, preferably, the sacrificial layer-forming
ink is selectively applied only to a part of the region that is
adjacent to the region that forms an outermost layer of the
three-dimensional shaped article and on the surface side of the
outermost layer.
[0031] This causes the three-dimensional shaped article that is
ultimately obtained to be one where a site that presents with a
glossy texture and a site that presents with another kind of
texture both exist, thus making it possible to render more complex
outer appearances and making it possible to give the
three-dimensional shaped article a particularly excellent aesthetic
appearance (aesthetics), luxuriousness, and the like.
[0032] A three-dimensional shaped article manufacturing apparatus
of the present invention is for manufacturing a three-dimensional
shaped article by laminating layers formed by discharging and
curing inks including a curable resin, the apparatus comprising: a
first discharge unit configured to discharge a substantive
section-forming ink to a region that forms the three-dimensional
shaped article; a second discharge unit configured to discharge a
sacrificial layer-forming ink for forming a sacrificial layer to a
region that is adjacent to a region that forms an outermost layer
of the three-dimensional shaped article and on a surface side of
the outermost layer; and a curing unit configured to cure the
substantive section-forming ink and the sacrificial layer-forming
ink, a viscoelasticity of the sacrificial layer-forming ink during
curing of the substantive section-forming ink being not less than a
viscoelasticity of the substantive section-forming ink during
curing of the substantive section-forming ink.
[0033] This makes it possible to provide a three-dimensional shaped
article manufacturing apparatus by which a three-dimensional shaped
article having a glossy texture can be manufactured stably and
efficiently.
[0034] An ink set of the present invention is used for
manufacturing a three-dimensional shaped article by laminating
layers formed by discharging and curing inks including a curable
resin, the ink set comprising: a substantive section-forming ink
applied to a region that forms the three-dimensional shaped
article; and a sacrificial layer-forming ink applied to a region
that is adjacent to a region that forms an outermost layer of the
three-dimensional shaped article and on a surface side of the
outermost layer, a viscoelasticity of the sacrificial layer-forming
ink during curing of the substantive section-forming ink being not
less than a viscoelasticity of the substantive section-forming ink
during curing of the substantive section-forming ink.
[0035] This makes it possible to provide an ink set by which a
three-dimensional shaped article having a glossy texture can be
manufactured stably and efficiently.
[0036] A three-dimensional shaped article of the present invention
is manufactured using the three-dimensional shaped article
manufacturing method of the present invention.
[0037] This makes it possible to provide a three-dimensional shaped
article having a glossy texture.
[0038] A three-dimensional shaped article of the present invention
is manufactured using the three-dimensional shaped article
manufacturing apparatus of the present invention.
[0039] This makes it possible to provide a three-dimensional shaped
article having a glossy texture.
[0040] A three-dimensional shaped article of the present invention
is manufactured using the ink set of the present invention.
[0041] This makes it possible to provide a three-dimensional shaped
article having a glossy texture.
BRIEF DESCRIPTION OF THE DRAWINGS
[0042] Referring now to the attached drawings which form a part of
this original disclosure:
[0043] FIGS. 1A to 1H are cross-sectional views schematically
illustrating respective steps as regards a preferred embodiment of
a method of manufacturing a three-dimensional shaped article of the
present invention; and
[0044] FIG. 2 is a cross-sectional view schematically illustrating
a preferred embodiment of an apparatus for manufacturing a
three-dimensional shaped article of the present invention.
DETAILED DESCRIPTION OF EMBODIMENTS
[0045] Preferred embodiments of the present invention shall now be
described in greater detail below, with reference to the
accompanying drawings.
[0046] <<Method of Manufacturing a Three-Dimensional Shaped
Article>>
[0047] First, a method of manufacturing a three-dimensional shaped
article in the present invention shall be described.
[0048] FIGS. 1A to 1H are cross-sectional views schematically
illustrating respective steps as regards a preferred embodiment of
a method of manufacturing a three-dimensional shaped article of the
present invention.
[0049] As illustrated in FIGS. 1A to 1H, a method of manufacturing
a three-dimensional shaped article 10 of the present embodiment
comprises: ink discharge steps (FIGS. 1A, 1C, 1E) in which a
substantive section-forming ink (first ink) 11' comprising a
curable resin and a sacrificial layer-forming ink (second ink) 12'
comprising a curable resin are discharged in a predetermined
pattern by inkjet; curing steps (FIGS. 1B, 1D, 1F) in which a layer
1 including a substantive section 11 and a sacrificial layer 12 is
formed by curing the discharged substantive section-forming ink 11'
and sacrificial layer-forming ink 12; these steps being
sequentially repeated to obtain a provisional molded article 10'
(FIG. 10), and thereafter a sacrificial layer removal step (FIG.
1H) in which the sacrificial layers 12 are removed.
[0050] In the ink discharge steps, the substantive section-forming
ink 11' is applied to a region that is to become the substantive
section 11 of the three-dimensional shaped article 10, and the
sacrificial layer-forming ink 12' is applied to a region which is
adjacent to a region that is to become an outermost layer of the
substantive section 11 of the three-dimensional shaped article 10
and which is on the surface side of the outermost layer.
[0051] The viscoelasticity of the sacrificial layer-forming ink 12'
during curing of the substantive section-forming ink 11' is not
less than the viscoelasticity of the substantive section-forming
ink 11' during curing of the substantive section-forming ink 11'.
"During curing" refers to a semi-cured state at a point in time
where the fluidity is lost when the substantive section-forming ink
11' is being cured.
[0052] Satisfying such conditions prevents an unintended wrinkling
from occurring at a site that is to become an outer surface of the
substantive section 11 when the substantive section-forming ink 11'
is being cured, and causes the three-dimensional shaped article 10
that is ultimately obtained to have a glossy outer appearance.
Satisfying the aforementioned conditions also makes it possible to
stably and efficiently manufacture the three-dimensional shaped
article 10.
[0053] It suffices for the viscoelasticity of the sacrificial
layer-forming ink 12' during curing of the substantive
section-forming ink 11' to not be less than the viscoelasticity of
the substantive section-forming ink 11' during curing of the
substantive section-forming ink 11', but preferably the
viscoelasticity of the sacrificial layer-forming ink 12' during
curing of the substantive section-forming ink 11' is greater than
the viscoelasticity of the substantive section-forming ink 11'
during curing of the substantive section-forming ink 11'. This
causes the effects of the present invention to be more prominently
exhibited.
[0054] In the present invention, it is possible to employ a value
obtained by measurement using a variety of viscoelasticity
measurement instruments (for example, ARES by Rheometric
Scientific, or the like) as the viscoelasticity, but it would also
be possible to determine the relationship between the
viscoelasticities of the two inks without actually measuring the
viscosity during curing of the substantive section-forming ink,
from, for example, the relationship between the initial viscosities
(the viscosities in the state prior to when the curing reaction is
allowed to proceed) of the substantive section-forming ink and the
sacrificial layer-forming ink, the relationship between the degrees
of curing of the two inks after the substantive section-forming ink
and the sacrificial layer-forming ink have been subjected to the
curing treatment under the same conditions, or the like.
[0055] Each of the steps shall now be described below.
[0056] <<Ink Discharge Steps (Ink Application
Steps)>>
[0057] In the ink discharge steps, the substantive section-forming
ink 11' comprising a curable resin and the sacrificial
layer-forming ink 12' comprising a curable resin are discharged in
a predetermined pattern by inkjet (FIGS. 1A, 1C, 1E).
[0058] More specifically, the substantive section-forming ink 11'
is applied to a region that is to become the substantive section 11
of the three-dimensional shaped article 10, and the sacrificial
layer-forming ink 12' is applied to a region which is adjacent to a
region that is to become an outermost layer of the substantive
section 11 of the three-dimensional shaped article 10 and which is
on the surface side of the outermost layer.
[0059] In the first of the ink discharge steps, the inks (the
substantive section-forming ink 11' and the sacrificial
layer-forming ink 12') are discharged onto a stage 3 (FIG. 1A), and
in the second and subsequent ink discharge steps, the inks (the
substantive section-forming ink 11' and the sacrificial
layer-forming ink 12') are discharged onto a layer 1 (FIGS. 1C,
1E).
[0060] In this manner, in the present embodiment, not only is ink
(the substantive section-forming ink 11') applied to the site that
is to become the substantive section 11 of the three-dimensional
shaped article 10, but also ink (the sacrificial layer-forming ink
12') is applied to the surface side thereof, as well.
[0061] So doing adjusts the surface shape of the three-dimensional
shaped article 10 and in particular prevents an unintended
wrinkling from being generated, thus producing a surface shape that
presents with a glossy outer appearance.
[0062] Applying the sacrificial layer-forming ink 12' and forming
the sacrificial layer 12 makes it possible for the substantive
section-forming ink 11' for forming an upper layer (second layer)
to be suitably supported by the sacrificial layer of a lower layer
(first layer), even for where a layer (second layer) constituting
the three-dimensional shaped article 10 has a portion bulging out
from an outer peripheral section of the layer (first layer)
therebelow (for example, the relationship between the first layer
and second layer from the bottom, the relationship between the
second layer and third layer from the bottom, and the relationship
between the fourth layer and fifth layer from the bottom in the
drawings). Therefore, unintended deformation (in particular,
sagging and the like) of the substantive section 11 can be suitably
prevented (the sacrificial layer 12 of the first layer functions as
a support material), and the three-dimensional shaped article 10
that is ultimately obtained can be given particularly excellent
dimensional accuracy.
[0063] In the present steps, the inks (the substantive
section-forming ink 11' and the sacrificial layer-forming ink 12')
are applied by inkjet, and therefore the inks can be applied with
favorable reproducibility even when the pattern of application of
the inks (the substantive section-forming ink 11' and the
sacrificial layer-forming ink 12') has a finely-detailed shape. As
a result, the three-dimensional shaped article 10 that is
ultimately obtained can be given particularly high dimensional
accuracy, and also the surface shape and appearance of the
three-dimensional shaped article 10 can be more suitably
controlled.
[0064] The substantive section-forming ink 11' and the sacrificial
layer-forming ink 12' shall be described in greater detail
below.
[0065] Though the amount of ink applied in the present steps is not
particularly limited, the thickness of the first layer formed in
the subsequent curing step is preferably 30 to 500 .mu.m, more
preferably 70 to 150 .mu.m.
[0066] This makes it possible to more effectively prevent, inter
alia, the occurrence of unintended irregularities in the
three-dimensional shaped article 10 that is manufactured, while
also giving the three-dimensional shaped article 10 ample and
excellent productivity, and makes it possible to give the
three-dimensional shaped article 10 particularly excellent
dimensional accuracy. The surface state and appearance of the
three-dimensional shaped article 10 that is ultimately obtained can
also be more suitably controlled.
[0067] <<Curing Steps (Layer Formation Steps)>>
[0068] After the inks (the substantive section-forming ink 11' and
the sacrificial layer-forming ink 12') have been applied
(discharged) in the ink discharge steps, the curing components
(curable resins) included in the inks (the substantive
section-forming ink 11' and the sacrificial layer-forming ink 12')
are cured (FIGS. 1B, 1D, 1F). This produces the layer 1 having the
substantive section 11 and the sacrificial layer 12.
[0069] The viscoelasticity of the substantive section-forming ink
11' and the viscoelasticity of the sacrificial layer-forming ink
12' when the substantive section-forming ink 11' and the
sacrificial layer-forming ink 12' are being cured in the present
steps (the instant where the substantive section-forming ink 11' is
cured) satisfy a predetermined relationship. Namely, the
viscoelasticity of the sacrificial layer-forming ink 12' during
curing of the substantive section-forming ink 11' is not less than
the viscoelasticity of the substantive section-forming ink 11'
during curing of the substantive section-forming ink 11'.
[0070] This makes it possible for the sacrificial layer-forming ink
12' to be prevented from moving microscopically during curing, and
makes it possible to prevent an unintended wrinkling from being
generated in the surface (site where the substantive
section-forming ink 11' has been in contact with the sacrificial
layer-forming ink 12') of the substantive section 11 due to the
stress during curing. As a result, the three-dimensional shaped
article 10 that is ultimately obtained is prevented from
experiencing an unintended wrinkling, has a smooth surface, and
presents with a glossy outer appearance.
[0071] Also, adjusting the duration from landing of the inks until
completion of curing (for example, the intensity of irradiation
with energy rays, or the like) makes it possible to easily and
reliably control the extent of the glossiness. As a result, the
three-dimensional shaped article 10 that is ultimately obtained can
be reliably given a desired appearance.
[0072] Also, curing the curing components (curable resins) included
in the inks in the present steps causes the three-dimensional
shaped article 10 that is ultimately obtained to be constituted of
a cured article, and therefore to have more excellent mechanical
strength, durability, and the like than a three-dimensional shaped
article constituted of, for example, a thermoplastic resin or the
like.
[0073] The present steps vary depending on the types of curing
components (curable resins), but, for example, in a case where the
curing components (curable resins) are heat-curable resins, the
present steps can be carried out by heating; in a case where the
curing components (curable resins) are photocurable resins, the
present steps can be carried out by irradiating with a
corresponding light (for example, the present steps can be carried
out by irradiating with ultraviolet rays in a case where the curing
components (curable resins) are ultraviolet-curable resins).
[0074] The description above posits applying the inks in a shape
and pattern corresponding to the layer 1 and thereafter curing the
entirety of the layer (layer corresponding to layer 1) constituted
of the inks, but in the present invention, the discharging of ink
and the curing of ink may also proceed simultaneously for at least
a partial region. That is to say, prior to when the entirety of the
pattern of the entirety of one layer 1 is formed, the curing
reaction may be allowed to proceed sequentially from a site to
which the inks were applied as regards at least a part of the
region corresponding to the layer 1. As regards at least a portion
of contact between the substantive section-forming ink 11' and the
sacrificial layer-forming ink 12' (a portion at which the
substantive section 11 and the sacrificial layer 12 are to be in
contact), however, the curing treatment (for example, curing with
ultraviolet rays, in a case where the curing components included in
the two inks are ultraviolet-curable resins) would be carried out
at the same time, and the curing treatment for the substantive
section-forming ink 11' and the curing treatment for the
sacrificial layer-forming ink 12' would not be performed
separately.
[0075] Also, in the present steps, there is no need to completely
cure the curing components included in the inks. For example, at
the end of the present steps, the sacrificial layer-forming ink 12'
may have achieved an incompletely cured state, the substantive
section-forming ink 11' having been cured at a higher degree of
cure than the sacrificial layer-forming ink 12'.
[0076] This makes it possible to easily perform the sacrificial
layer removal step described below, and makes it possible to
further improve the productivity of the three-dimensional shaped
article 10.
[0077] At the end of the present steps, also, a state where the
substantive section-forming ink 11' has been cured in an incomplete
state may also be achieved. In such a case, too, the
three-dimensional shaped article 10 that is ultimately obtained can
be given excellent mechanical strength and the like by, for
example, carrying out a true curing step for raising the degree of
cure with respect to the substantive section-forming ink 11' (the
substantive section 11) that is in the incomplete curing state
after having carried out a later step (for example, the "ink
discharge step" that follows formation of the underlying layer 1 in
the curing steps, or the like). Also, applying the ink for forming
an upper layer in the state where the substantive section-forming
ink 11' (lower layer) has been cured in the incomplete state makes
it possible to impart particularly excellent adhesion between the
layers.
[0078] The aforementioned sequence of steps is repeatedly carried
out. This achieves a state where the layers 1 adjacent to one
another are bonded together, and produces a laminate in which a
plurality of the layers 1 in such a state have been laminated,
i.e., the provisional molded article 10' in which the sacrificial
layers 12 are provided to the surfaces of the substantive sections
11 (see FIG. 1G).
[0079] <<Sacrificial Layer Removal Step>>
[0080] After the aforementioned sequence of steps has been
repeatedly carried out, the sacrificial layers 12 are removed (FIG.
1H).
[0081] This produces a three-dimensional shaped article 10 on which
the flat-surfaced substantive section 11, where no unintended
wrinkling has been generated, is exposed. This three-dimensional
shaped article 10 has a glossy texture.
[0082] Examples of methods of removing the sacrificial layers could
include a method with which a liquid that selectively dissolves the
sacrificial layers 12 is used to selectively dissolve and remove
the sacrificial layers 12; or a method with which a liquid that has
higher absorption by the sacrificial layers 12 than the substantive
section 11 is used to cause the liquid to be selectively absorbed
into the sacrificial layers 12, thereby expanding the sacrificial
layers 12, or lowering the mechanical strength of the sacrificial
layers 12 whereupon the sacrificial layers 12 are peeled off or
destroyed.
[0083] The liquid used in the present step would vary depending on
the constituent materials of the substantive section 11 and the
sacrificial layers 12, and the like, but examples that could be
used include: water; methanol, ethanol, isopropyl alcohol, n-propyl
alcohol, butanol, isobutanol, and other alcohols; or glycerin,
ethylene glycol, diethylene glycol, triethylene glycol, propylene
glycol, dipropylene glycol, and other glycols. The liquid may
comprise one or more species selected from these, and may also
have: a water-soluble substance that produces hydroxide ions of
sodium hydroxide, potassium hydroxide, sodium hydrogen carbonate,
or organic amines in order to improve the dissolubility of the
sacrificial layers; a surfactant that facilitates separation of the
sacrificial layers that have been peeled off; or the like that is
mixed therein.
[0084] Though not particularly limited, examples of the method of
applying the aforementioned liquid to the provisional molded
article 10' could include employing a variety of methods such as
immersion, spraying, or coating.
[0085] The description above posits that a liquid is used, but a
substance (for example, a solid, gas, supercritical fluid, or the
like) that has a similar function may also be used.
[0086] Ultrasonic vibrations may also be applied when the liquid is
being applied or after the liquid has been applied.
[0087] This makes it possible to facilitate the removal of the
sacrificial layers 12 and makes it possible to give the
three-dimensional shaped article 10 particularly excellent
productivity.
[0088] In the present invention, the surface state (flat surface
state where no unintended wrinkling has been generated) of the
substantive section 11 of the three-dimensional shaped article 10
can be viewed in the state of the provisional molded article 10';
in a case where a glossy outer appearance is presented, the
sacrificial layers 12 need not be removed, but removing the
sacrificial layers 12 as in the present embodiment makes it
possible for the flat surface state where no unintended wrinkling
has been generated to be suitably viewed by an observer, because
the substantive section 11 is exposed. For this reason, the effects
of the present invention are more prominently exhibited.
[0089] The description above posits that the sacrificial
layer-forming ink 12' is applied so as to be in contact with the
substantive section-forming ink 11' in the entire region that is to
become the outermost layer of the three-dimensional shaped article
10, but the sacrificial layer-forming ink 12' may instead be
applied so as to be in contact with the substantive section-forming
ink 11' only in a part of the region that is to become the
outermost layer of the three-dimensional shaped article 10.
[0090] This causes the three-dimensional shaped article 10 that is
ultimately obtained to be one where a site that presents with a
glossy texture and a site that presents with another kind of
texture both exist, thus making it possible to render more complex
outer appearances and making it possible to give the
three-dimensional shaped article 10 a particularly excellent
aesthetic appearance (aesthetics), luxuriousness, and the like.
[0091] According to the method of manufacture of the present
invention as described above, a three-dimensional shaped article
that has a glossy texture can be manufactured stably and
efficiently. Also, the yield of the three-dimensional shaped
article is improved and therefore the present invention is also
advantageous in terms of reducing the costs of manufacturing the
three-dimensional shaped article.
[0092] <<Apparatus for Manufacturing a Three-Dimensional
Shaped Article>>
[0093] First, the apparatus for manufacturing a three-dimensional
shaped article of the present invention shall be described.
[0094] FIG. 2 is a cross-sectional view schematically illustrating
a preferred embodiment of an apparatus for manufacturing a
three-dimensional shaped article of the present invention.
[0095] An apparatus 100 for manufacturing a three-dimensional
shaped article is one that manufactures the three-dimensional
shaped article 10 by using the substantive section-forming ink 11'
and the sacrificial layer-forming ink 12' to repeatedly mold and
laminate the layers 1.
[0096] As illustrated in FIG. 2, the apparatus 100 for
manufacturing a three-dimensional shaped article has: a control
unit 2; the stage 3; a first ink discharge unit (substantive
section-forming ink applying means) 4 for discharging the
substantive section-forming ink 11; a second ink discharge unit
(sacrificial layer-forming ink applying means) 5 for discharging
the sacrificial layer-forming ink 12', and an energy ray
irradiating means (curing means) 6 for irradiating with energy rays
for curing the substantive section-forming ink 11' and the
sacrificial layer-forming ink 12'.
[0097] The control unit 2 has a computer 21 and a drive control
unit 22.
[0098] The computer 21 is, inter alia, a common desktop computer
configured to be provided with a CPU, memory, and the like inside.
The computer 21 converts the shape of the three-dimensional shaped
article 10 into data in the form of the model data, which is then
sliced into many parallel layers of thin cross-sections to obtain
cross-sectional data (slice data) that is then outputted to the
drive control unit 22.
[0099] The drive control unit 22 functions as a controlling means
for respectively driving the first ink discharge unit (substantive
section-forming ink applying means) 4, the second discharge unit
(sacrificial layer-forming ink applying means) 5, the energy ray
irradiating means (curing means) 6, and the like. A more specific
example of what is controlled is the discharged pattern and
discharged amount of the substantive section-forming ink 11' from
the first ink discharge unit (substantive section-forming ink
applying means) 4, the discharged pattern and discharged amount of
the sacrificial layer-forming ink 12' from the second discharge
unit (sacrificial layer-forming ink applying means) 5, the
irradiated amount and irradiation timing of the energy rays from
the energy ray irradiating means (curing means) 6, and the
like.
[0100] The stage 3 is a region where the substantive
section-forming ink 11' and the sacrificial layer-forming ink 12'
are applied.
[0101] The stage 3 is one that has a flat surface (the site where
the substantive section-forming ink 11' and the sacrificial
layer-forming ink 12' are applied).
[0102] This makes it possible to easily and reliably form layers 1
that have a highly uniform thickness. It is also possible to
effectively prevent unintended deformation or the like from taking
place in the three-dimensional shaped article 10 that is
manufactured.
[0103] The stage 3 is preferably constituted of a high-strength
material. Examples of the constituent material of the stage 3
include a variety of metal materials such as stainless steel.
[0104] The surface (site where the substantive section-forming ink
11' and the sacrificial layer-forming ink 12' are applied) of the
stage 3 may also be subjected to a surface treatment.
[0105] This makes it possible, for example, to more effectively
prevent the constituent material of the substantive section-forming
ink 11' and the constituent material of the sacrificial
layer-forming ink 12' from adhering to the stage 3, to give the
stage 3 excellent durability, to achieve production of the
three-dimensional shaped article 10 that has long-term stability,
and so forth. Examples of the material used for the surface
treatment of the surface of the stage 3 could include a fluorine
resin such as polytetrafluoroethylene, or the like.
[0106] The first ink discharge unit (substantive section-forming
ink applying means) 4 is one that discharges the substantive
section-forming ink 11' by inkjet.
[0107] Providing such a first ink discharge unit (substantive
section-forming ink applying means) 4 makes it possible to apply a
desired amount of the substantive section-forming ink 11' to a
desired site with a finely-detailed pattern, and makes it possible
to manufacture even the three-dimensional shaped article 10, which
has a finely-detailed structure, at particularly favorable
productivity.
[0108] For the liquid droplet discharge format (inkjet format), it
would be possible to use a piezoelectric format, a format for
discharging the ink using bubbles generated by heating the ink, or
the like, but a piezoelectric format is preferable in terms of the
difficulty of altering the constituent components of the ink and
the like.
[0109] With the first ink discharge unit (substantive
section-forming ink applying means) 4, a command coming from the
drive control unit 22 controls the pattern that is to be formed,
the amount of substantive section-forming ink 11' applied, and the
like. The discharged pattern, discharged amount, and the like of
the substantive section-forming ink 11' from the first ink
discharge unit (substantive section-forming ink applying means) 4
are determined on the basis of the slice data.
[0110] This makes it possible to apply a necessary and sufficient
amount of the substantive section-forming ink 11' to a target site,
makes it possible to reliably form the substantive section 11 of
the desired pattern, and makes it possible to give the
three-dimensional shaped article 10 more reliably excellent
dimensional accuracy and mechanical strength. Also, in a case where
the substantive section-forming ink 11' is one that comprises a
coloring agent, then the desired color tone, patterning, and the
like can be obtained.
[0111] The first ink discharge unit (substantive section-forming
ink applying means) 4 has the ability to move in the X-direction
and the Y-direction relative to the stage, and also has the ability
to move in the Z-direction.
[0112] This makes it possible to uphold the desired value of
distance between a nozzle surface (discharge unit distal end) of
the first ink discharge unit (substantive section-forming ink
applying means) 4 and a section of landing of the substantive
section-forming ink 11' even in a case where the layers 1 have been
laminated.
[0113] The second ink discharge unit (sacrificial layer-forming ink
applying means) 5 is one that discharges the sacrificial
layer-forming ink 12' by inkjet.
[0114] Providing such a second ink discharge unit (sacrificial
layer-forming ink forming ink applying means) 5 makes it possible
to apply a desired amount of the sacrificial layer-forming ink 12'
to a desired site with a finely-detailed pattern, and makes it
possible, even when the three-dimensional shaped article 10 that is
to be manufactured has a finely-detailed structure, to form
sacrificial layers 12 of the desired size and shape at the desired
shapes, thus making it possible to more reliably form the surface
shape and outer appearance of the three-dimensional shaped article
10. It is also possible to give the three-dimensional shaped
article 10 particularly excellent productivity.
[0115] The format of ink droplet discharge (inkjet format),
control, driving, and the like as regards the second ink discharge
unit (sacrificial layer-forming ink applying means) 5 are similar
to those described above for the first ink discharge unit
(substantive section-form ing ink applying means) 4.
[0116] The energy ray irradiating means (curing means) 6 is one
that irradiates with energy rays for curing the substantive
section-forming ink 11' and the sacrificial layer-forming ink
12'.
[0117] Providing the curing means 6 of such description makes it
possible to give the three-dimensional shaped article 10 that is
ultimately obtained excellent mechanical strength and also makes it
possible to reliably control the surface shape and outer appearance
of the three-dimensional shaped article 10.
[0118] The energy ray irradiating means (curing means) 6 is one
that has an irradiation surface area that allows for the
substantive section-forming ink 11' and the sacrificial
layer-forming ink 12' to be irradiated with the energy rays at the
same time, as regards at least the portion of contact between the
substantive section-forming ink 11' and the sacrificial
layer-forming ink 12' (the portion at which the substantive section
11 and the sacrificial layer 12 are to be in contact with one
another).
[0119] The type of energy rays with which the energy ray
irradiating means (curing means) 6 irradiates will vary depending
on the constituent materials of the substantive section-forming ink
11' and the sacrificial layer-forming ink 12', but examples include
ultraviolet rays, visible light rays, infrared rays, X-rays, gamma
rays, an electron beam, an ion beam, or the like. In particular, it
would be preferable to use ultraviolet rays in terms of costs and
the productivity of the three-dimensional shaped article.
[0120] Though not illustrated in the drawings, the apparatus 100
for manufacturing a three-dimensional shaped article may be one
that is provided with a sacrificial layer removing means for
removing the sacrificial layers 12, and a drying means for drying
the three-dimensional shaped article 10 from which the sacrificial
layers have been removed.
[0121] Examples of a sacrificial layer removing means include one
that mechanically destroys and removes the sacrificial layers 12, a
tank which holds the liquid as described above and in which the
provisional molded article 10' is immersed, a liquid spraying means
for spraying the liquid as described above toward the provisional
molded article 10', a liquid coating means for coating the
provisional molded article 10' with the liquid as described above,
and so forth.
[0122] Examples of a drying means include one that supplies a
heated gas or dried gas, as described above, or a pressure-reducing
means that reduces the pressure of a space in which the
three-dimensional shaped article 10 is held.
[0123] The apparatus for manufacturing a three-dimensional shaped
article of the present invention need only perform at least a part
of the steps described above, and a part of the steps described
above may be performed without using the apparatus for
manufacturing a three-dimensional shaped article.
[0124] According to the apparatus for manufacturing a
three-dimensional shaped article of the present invention described
above, a three-dimensional shaped article that has a glossy texture
can be manufactured stably and efficiently. Also, the yield of the
three-dimensional shaped article is improved and therefore the
present invention is also advantageous in terms of reducing the
costs of manufacturing the three-dimensional shaped article.
[0125] <<Ink Set>>
[0126] Next, the ink set of the present invention shall be
described.
[0127] The ink set of the present invention comprises at least one
kind of substantive section-forming ink 11' and at least one kind
of sacrificial layer-forming ink 12'. The ink set of the present
invention is one that is applied to the method of manufacturing a
three-dimensional shaped article and apparatus for manufacturing a
three-dimensional shaped article in the present invention as
described above.
[0128] <Substantive Section-Forming Ink>
[0129] The substantive section-forming ink 11' comprises at least a
curable resin (curing component).
[0130] (Curable Resin)
[0131] Examples of the curable resin (curing component) include: a
heat-curable resin; a variety of photocurable resins, such as a
visible light-curable resin (a photocurable resin in the narrow
sense) that is cured by light in the visible light range, an
ultraviolet ray-curable resin, or an infrared ray-curable resin; an
X-ray curable resin; and the like, from which one kind can be
selected for use, or two or more kinds can be combined for use.
[0132] It is particularly preferable to use an ultraviolet
ray-curable resin (polymerizable compound) in terms of the
mechanical strength of the resulting three-dimensional shaped
article 10, the productivity of the three-dimensional shaped
article 10, the storage stability of the substantive
section-forming ink 11', and so forth.
[0133] Preferably used as an ultraviolet ray-curable resin
(polymerizable compound) is one with which an addition
polymerization or ring-opening polymerization is initiated by
radical species or cation species or the like produced from a
photopolymerization initiator by irradiation with ultraviolet rays,
thus creating a polymer. Manners of polymerization in addition
polymerization include radical, cationic, anionic, metathesis, and
coordination polymerization. Manners of polymerization in
ring-opening polymerization include cationic, anionic, radical,
metathesis, and coordination polymerization.
[0134] Examples of addition polymerizable compounds include
compounds that have at least one ethylenically unsaturated double
bond. Compounds that have at least one, preferably two terminal
ethylenically unsaturated bonds can be preferably used as an
addition polymerizable compound.
[0135] Ethylenically unsaturated polymerizable compounds have the
chemical form of monofunctional polymerizable compounds and
polyfunctional polymerizable compounds, or mixtures thereof.
[0136] Examples of monofunctional polymerizable compounds include
unsaturated carboxylic acids (for example, acrylic acid,
methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid,
maleic acid, and the like) or esters or amides thereof.
[0137] Polyfunctional polymerizable compounds includes esters of
unsaturated carboxylic acids and aliphatic polyhydric alcohol
compounds, and amides of unsaturated carboxylic acids and aliphatic
amine compounds.
[0138] It would also be possible to use: a product of an addition
reaction between an isocyanate or an epoxy and an unsaturated
carboxylic acid ester or amide that has a nucleophilic substituent
such as a hydroxyl group, an amino group, or a mercapto group; a
product of a dehydration condensation reaction with a carboxylic
acid; or the like. It would also be possible to use: the product of
an addition reaction between an unsaturated carboxylic acid ester
or amide having an electrophilic substituent group such as an
isocyanate group or an epoxy group and an alcohol, amine, or thiol;
or the product of a substitution reaction between an unsaturated
carboxylic acid ester or amide having a leaving group substituent
such as a halogen group or a tosyloxy group and an alcohol, amine,
or thiol.
[0139] A (meth)acrylic acid ester is representative as a specific
example of a radical polymerizable compound that is the ester of an
unsaturated carboxylic acid and an aliphatic polyhydric alcohol
compound; either a monofunctional one or a polyfunctional one could
be used.
[0140] Specific examples of a monofunctional (meth)acrylate
include: tolyloxyethyl(meth)acrylate, phenyloxyethyl(meth)acrylate,
cyclohexyl(meth)acrylate, ethyl(meth)acrylate,
methyl(meth)acrylate, isobornyl(meth)acrylate, dipropylene glycol
di(meth)acrylate, tetrahydrofurfuryl(meth)acrylate, ethoxyethoxy
ethyl(meth)acrylate, 2-(2-vinyloxyethoxy)ethyl(meth)acrylate,
2-hydroxy-3-phenoxypropyl(meth)acrylate,
4-hydroxybutyl(meth)acrylate, and the like.
[0141] Specific examples of bifunctional (meth)acrylates include
ethylene glycol di(meth)acrylate, triethylene glycol
di(meth)acrylate, 1,3-butanediol di(meth)acrylate, tetramethylene
glycol di(meth)acrylate, propylene glycol di(meth)acrylate,
neopentyl glycol di(meth)acrylate, hexanediol di(meth)acrylate,
1,4-cyclohexanediol di(meth)acrylate, tetraethylene glycol
di(meth)acrylate, pentaerythritol di(meth)acrylate, and
dipentaerythritol di(meth)acrylate.
[0142] Specific examples of trifunctional (meth)acrylates include
trimethylol propane tri(meth)acrylate, trimethylol ethane
tri(meth)acrylate, trimethylolpropane alkylene oxide-modified
tri(meth)acrylate, pentaerythritol tri(meth)acrylate,
dipentaerythritol tri(meth)acrylate, trimethylol propane
tri((meth)acryloyloxypropyl) ether, isocyanuric acid alkylene
oxide-modified tri(meth)acrylate, propionic acid dipentaerythritol
tri(meth)acrylate, tri((meth)acryloyloxyethyl) isocyanurate,
hydroxypivalaldehyde-modified dimethylol propane tri(meth)acrylate,
and sorbitol tri(meth)acrylate.
[0143] Specific examples of tetrafunctional (meth)acrylates include
pentaerythritol tetra(meth)acrylate, sorbitol tetra(meth)acrylate,
ditrimethylol propane tetra(meth)acrylate, propionic acid
dipentaerythritol tetra(meth)acrylate, and ethoxylated
pentaerythritol tetra(meth)acrylate.
[0144] Specific examples of pentafunctional (meth)acrylates)
include sorbitol penta(meth)acrylate, and dipentaerythritol
penta(meth)acrylate.
[0145] Specific examples of hexafunctional (meth)acrylates include
dipentaerythritol hexa(meth)acrylate, sorbitol hexa(meth)acrylate,
phosphazene alkylene oxide-modified hexa(meth)acrylate, and
captolactone-modified dipentaerythritol hexa(meth)acrylate.
[0146] Examples of polymerizable compounds other than
(meth)acrylates include itaconic acid esters, crotonic acid esters,
isocrotonic acid esters, and maleic acid esters.
[0147] Examples of itaconic acid esters include ethylene glycol
diitaconate, propylene glycol diitaconate, 1,3-butanediol
diitaconate, 1,4-butanediol diitaconate, tetramethylene glycol
diitaconate, pentaerythritol diitaconate, and sorbitol
tetraitaconate.
[0148] Examples of crotonic acid esters include ethylene glycol
dicrotonate, tetramethylene glycol dicrotonate, pentaerythritol
dicrotonate, and sorbitol tetradicrotonate.
[0149] Examples of isocrotonic acid esters include ethylene glycol
diisocrotonate, pentaerythritol diisocrotonate, and sorbitol
tetraisocrotonate.
[0150] Examples of maleic acid esters include ethylene glycol
dimaleate, triethylene glycol dimaleate, pentaerythritol dimaleate,
and sorbitol tetramaleate.
[0151] Examples of other esters that can be used also include: the
aliphatic alcohol esters disclosed in Japanese Examined Patent
Publication No. S46-27926, Japanese Examined Patent Publication No.
S51-47334, and Japanese Unexamined Patent Publication No.
S57-196231; those having an aromatic backbone disclosed in Japanese
Unexamined Patent Publication No. S59-5240, Japanese Unexamined
Patent Publication No. S59-5241, and Japanese Unexamined Patent
Publication No. H2-226149; and the one containing an amino group
disclosed in Japanese Unexamined Patent Publication No.
H1-165613.
[0152] Specific examples of monomers of an amide of an unsaturated
carboxylic acid and an aliphatic amine compound include methylene
bis-acrylamide, methylene bismethacrylamide, 1,6-hexamethylene
bis-acrylamide, 1,6-hexamethylene bismethacrylamide,
diethylenetriamine trisacrylamide, xylylene bisacrylamide xylylene
bismethacrylamide, and (meth)acryloylmorpholine.
[0153] Another example of a preferable amide monomer would be the
one having a cyclohexylene structure disclosed in Japanese Examined
Patent Publication No. 554-21726.
[0154] Urethane-based addition polymerizable compounds manufactured
using an addition reaction between an isocyanate and a hydroxyl
group are also favorable, and a specific example thereof could be a
vinyl urethane compound containing two or more polymerizable vinyl
groups in a molecule obtained by adding a vinyl monomer containing
a hydroxyl group represented in formula (1) below to a
polyisocyanate compound having two or more isocyanate groups in one
molecule, as is disclosed in Japanese Examined Patent Publication
No. S48-41708.
CH.sub.2.dbd.C(R.sup.1)COOCH.sub.2CH(R.sup.2)OH (1)
[0155] (where R.sup.1 and R.sup.2 in the formula (1) each
independently indicate an H or CH.sub.3)
[0156] In the present invention, a cationic ring-opening
polymerizable compound having one or more cyclic ether groups such
as an epoxy group or an oxetane group in the molecule can be
favorably used as an ultraviolet ray-curable resin (polymerizable
resin).
[0157] Examples of cationic polymerizable compounds include curable
compounds comprising a ring-opening polymerizable group, among
which heterocyclic group-containing curable compounds are
particularly preferable. Examples of such curable compounds include
an epoxy derivative, an oxetane derivative, a tetrahydrofuran
derivative, a cyclic lactone derivative, a cyclic carbonate
derivative, an oxazoline derivative, or other such cyclic imino
ethers, or vinyl ethers; of these, epoxy derivatives, oxetane
derivatives, and vinyl ethers are preferable.
[0158] Examples of preferable epoxy derivatives include
monofunctional glycidyl ethers, polyfunctional glycidyl ethers,
monofunctional alicyclic epoxies, and polyfunctional alicyclic
epoxies.
[0159] Specific compounds for glycidyl ethers can be illustratively
exemplified by diglycidyl ethers, (for example, ethylene glycol
diglycidyl ether, bisphenol A diglycidyl ether, and the like),
trifunctional or higher glycidyl ethers (for example, trimethylol
ethane triglycidyl ether, trimethylol propane triglycidyl ether,
glycerol triglycidyl ether, triglycidyl trishydroxyethyl
isocyanurate, or the like), tetrafunctional or higher glycidyl
ethers (for example, sorbitol tetraglycidyl ether, pentaerythritol
tetraglycyl ether, cresol novolac resin polyglycidyl ether,
phenolnovolac resin polyglycidyl ether, and the like), alicyclic
epoxyies (for example, Celloxide 2021P, Celloxide 2081, Epolead
GT-301, and Epolead GT-401 (Daicel Chemical Industries)), EHPE
(Daicel Chemical Industries), phenol novolac resin polycyclohexyl
epoxy methyl ether or the like), and oxetanes (for example, OX-SQ,
PNOX-1009 (Toagosei), and the like).
[0160] As a polymerizable compound, an alicyclic epoxy derivative
could be preferably used. An "alicyclic epoxy group" is a term for
a moiety obtained when a double bond of a cycloalkene group such as
a cyclopentene group or cyclohexene group is epoxidized with a
suitable oxidizing agent such as hydrogen peroxide or a peroxy
acid.
[0161] Preferable alicyclic epoxy compounds include polyfunctional
alicyclic epoxies having two or more cyclohexene oxide groups or
cyclopentene oxide groups in one molecule. Specific examples of
alicyclic epoxy compounds include 4-vinylcyclohexene dioxide,
(3,4-epoxycyclohexyl)methyl-3,4-epoxycyclohexyl carboxylate,
di(3,4-epoxycyclohexyl) adipate, di(3,4-epoxycyclohexylmethyl)
adipate, bis(2,3-epoxycyclopentyl) ether,
di(2,3-epoxy-6-methylcyclohexylmethyl) adipate, and
dicyclopentadiene dioxide.
[0162] A glycidyl compound having a normal epoxy group without an
alicyclic structure in the molecule could be used either
independently or in combination with an aforementioned alicyclic
epoxy compound.
[0163] Examples of such normal glycidyl compounds could include
glycidyl ether compounds and glycidyl ester compounds, but it is
preferable to use a glycidyl ether compound in combination.
[0164] Specific examples of glycidyl ether compounds include: an
aromatic glycidyl ether compound such as
1,3-bis(2,3-epoxypropyloxy)benzene, a bisphenol A epoxy resin, a
bisphenol F epoxy resin, a phenol novolac epoxy resin, a cresol
novolac epoxy resin, and a trisphenol methane epoxy resin; and an
aliphatic glycidyl ether compound such as 1,4-butanediol glycidyl
ether, glycerol triglycidyl ether, propylene glycol diglycidyl
ether, and trimethylol propane tritriglycidyl ether. Examples of a
glycidyl ester could include a glycidyl ester of linoleic acid
dimers.
[0165] As a polymerizable compound, it would be possible to use a
compound that has an oxetanyl group, which is a four-membered
cyclic ether (this compound also being called simply an "oxetane
compound" below). An oxetanyl group-containing compound is a
compound that has one or more oxetanyl groups in one molecule.
[0166] Of the aforementioned curing components, the substantive
section-forming ink 11' is particularly preferably one that
comprises one or more species selected from the group consisting of
2-(2-vinyloxyethoxy)ethyl(meth)acrylate, a polyether-based
aliphatic urethane(meth)acrylate oligomer,
2-hydroxy-3-phenoxypropyl(meth)acrylate, and
4-hydroxybutyl(meth)acrylate.
[0167] This makes it possible to cure the substantive
section-forming ink 11' at a more appropriate speed of curing,
causes the glossy outer appearance to be more reliably obtained in
the three-dimensional shaped article 10, and makes it possible to
provide the three-dimensional shaped article 10 with particularly
excellent productivity.
[0168] The substantive section 11 that is formed by curing the
substantive section-forming ink 11' can also be given particularly
excellent mechanical strength and shape stability. As a result, the
three-dimensional shaped article 10 can be given particularly
excellent strength, durability, and reliability.
[0169] Comprising these curing components also makes it possible to
give the cured product of the substantive section-forming ink 11'
particularly low swellability and solubility with respect to a
variety of solvents (for example, water and the like). As a result,
the sacrificial layers 12 can be removed more reliably and at
higher selectivity in the sacrificial layer removal step, and
unintended deformation due to a defect being produced in the
substantive section 11 or the like can be prevented. This results
in the ability to more reliably give the three-dimensional shaped
article 10 higher dimensional accuracy.
[0170] Also, because the cured product of the substantive
section-forming ink 11' can be given lower swellability (solvent
absorption), it is possible, for example, to omit or simplify a
drying treatment serving as post-treatment after the sacrificial
layer removal step. Because the solvent resistance of the
three-dimensional shaped article 10 that is ultimately obtained is
also improved, the three-dimensional shaped article 10 is given
particularly high reliability.
[0171] In particular, when the substantive section-forming ink 11'
comprises 2-(2-vinyloxyethoxy)ethyl(meth)acrylate, the substantive
section-forming ink 11' is less susceptible to oxygen inhibition
and can be cured at lower energy; also, copolymerization comprising
other monomers can be promoted, and the three-dimensional shaped
article 10 can be given particularly high strength.
[0172] When the substantive section-forming ink 11' comprises a
polyether-based aliphatic urethane(meth)acrylate oligomer, the
three-dimensional shaped article 10 can be given higher levels of
both strength and toughness.
[0173] When the substantive section-forming ink 11' comprises
2-hydroxy-3-phenoxypropyl(meth)acrylate, the substantive
section-forming ink 11' possesses flexibility and the elongation at
break can be improved.
[0174] When the substantive section-forming ink 11' comprises
4-hydroxybutyl(meth)acrylate, then the adhesion to PMMA or PEMA
particles, silica particles, metal particles, and the like is
improved and the three-dimensional shaped article 10 can be given
particularly high strength.
[0175] In a case where the substantive section-forming ink 11'
comprises the aforementioned specific curing components (one or
more species selected from the group consisting of
2-(2-vinyloxyethoxy)ethyl(meth)acrylate, polyether-based aliphatic
urethane(meth)acrylate oligomer,
2-hydroxy-3-phenoxypropyl(meth)acrylate, and
4-hydroxybutyl(meth)acrylate), then the proportion of these
specific curing components with respect to the total curing
components constituting the substantive section-forming ink 11' is
preferably 80 mass % or higher, more preferably 90 mass % or
higher, even more preferably 100 mass %. This causes the above such
effects to be more prominently exhibited.
[0176] The content ratio of the curing components in the
substantive section-forming ink 11' is preferably 80 to 97 mass %,
more preferably 85 to 95 mass %.
[0177] This makes it possible to impart particularly excellent
mechanical strength to the three-dimensional shaped article 10 that
is ultimately obtained. It is also possible to give the
three-dimensional shaped article 10 particularly excellent
productivity.
[0178] (Polymerization Initiator)
[0179] Preferably, the substantive section-forming ink 11'
comprises a polymerization initiator.
[0180] This makes it possible to accelerate the speed of curing of
the substantive section-forming ink 11' during the manufacture of
the three-dimensional shaped article 10, and makes it possible to
give the three-dimensional shaped article 10 particularly excellent
productivity.
[0181] Examples of polymerization initiators that can be used
include a photo-radical polymerization initiator (an aromatic
ketone, acyl phosphine oxide compound, aromatic onium salt
compound, organic peroxide, thio compound (a thioxanthone compound,
a thiophenyl group-containing compound, or the like), a hexaaryl
biimidazole compound, a ketoxime ester compound, a borate compound,
an azinium compound, a metallocene compound, an active ester
compound, a compound having a carbon-halogen bond, an alkylamine
compound, or the like) or a photo-cationic polymerization
initiator. Specific examples include acetophenone,
acetophenonebenzylketal, 1-hydroxycyclohexyl phenyl ketone,
2,2-dimethoxy-2-phenylacetophenone, xanthone, fluorenone,
benzaldehyde, fluorene, anthraquinone, triphenylamine, carbazole,
3-methylacetophenone, 4-chlorobenzophenone,
4,4'-dimethoxybenzophenone, 4,4'-diamino-benzophenone, Michler's
ketone, benzoin isopropyl ether, benzoin ethyl ether, benzyl
dimethyl ketal,
1-(4-isopropylphenyl)-2-hydroxy-2-methylpropan-1-one,
2-hydroxy-2-methyl-1-phenylpropan-1-one, thioxanethone,
diethylthioxanthone, 2-isopropylthioxanthone, 2-chlorothioxanthone,
2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-propan-1-one,
bis-(2,4,6-trimethylbenzoyl)-phenylphosphine oxide,
2,4,6-trimethylbenzoyl-diphenyl-phosphineoxide,
2,4-diethylthioxantone, and
bis-(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentyl phosphineoxide,
from which one species can be selected for use, or two or more
species can be combined for use.
[0182] Of these, a preferable polymerization initiator constituting
the substantive section-forming ink 11' is one that comprises
bis(2,4,6-trimethylbenzoyl)-phenyl phosphoneoxide and/or
2,4,6-trimethylbenzoyl-diphenyl-phosphoneoxide.
[0183] Comprising such a polymerization initiator makes it possible
to cure the substantive section-forming ink IP at a more
appropriate speed of curing, causes the glossy outer appearance to
be more reliably obtained in the three-dimensional shaped article
10, and makes it possible to give the three-dimensional shaped
article 10 particularly excellent productivity.
[0184] The substantive section 11 that is formed by curing the
substantive section-forming ink 11' can also be given particularly
excellent mechanical strength and shape stability. As a result, the
three-dimensional shaped article 10 can be given particularly
excellent strength, durability, and reliability.
[0185] In particular, along with the sacrificial layer-forming ink
12', which shall be described below, when the substantive
section-forming ink 11' comprises
bis(2,4,6-trimethylbenzoyl)-phenyl phosphineoxide and
(2,4,6-trimethylbenzoyl)-diphenyl phosphineoxide as a
polymerization initiator, then the speeds of curing of the
substantive section-forming ink 11' and the sacrificial
layer-forming ink 12' can be more suitably controlled and the
glossy outer appearance is even more reliably obtained in the
three-dimensional shaped article 10. The three-dimensional shaped
article 10 can also be given even more excellent productivity.
[0186] In a case where the substantive section-forming ink 11',
along with the sacrificial layer-forming ink 12' described below,
is one that comprises bis(2,4,6-trimethylbenzoyl)-phenyl
phosphineoxide as a polymerization initiator, then the content
ratio of the bis(2,4,6-trimethylbenzoyl)-phenyl phosphineoxide in
the substantive section-forming ink 11' is preferably higher than
the content ratio of the bis(2,4,6-trimethylbenzoyl)-phenyl
phosphineoxide in the sacrificial layer-forming ink 12'.
[0187] This makes it possible to cure the substantive
section-forming ink 11' and the sacrificial layer-forming ink 12'
each at a more suitable speed, and causes the glossy outer
appearance to be even more reliably obtained in the
three-dimensional shaped article 10.
[0188] In a case where the substantive section-forming ink 11',
along with the sacrificial layer-forming ink 12' described below,
is one that comprises 2,4,6-trimethylbenzoyl-diphenyl
phosphineoxide as a polymerization initiator, then the content
ratio of the 2,4,6-trimethylbenzoyl-diphenyl phosphineoxide in the
substantive section-forming ink 11' is preferably higher than the
content ratio of the 2,4,6-trimethylbenzoyl-diphenyl phosphineoxide
in the sacrificial layer-forming ink 12'.
[0189] This makes it possible to cure the substantive
section-forming ink 11' and the sacrificial layer-forming ink 12'
each at a more suitable speed, and causes the glossy outer
appearance to be even more reliably obtained in the
three-dimensional shaped article 10.
[0190] The content ratio of the polymerization initiator in the
substantive section-forming ink 11' is not particularly limited but
is preferably higher than the content ratio of the polymerization
initiator in the sacrificial layer-forming ink 12'.
[0191] This makes it possible to cure the substantive
section-forming ink 11' and the sacrificial layer-forming ink 12'
each at a more suitable speed, and causes the glossy outer
appearance to be even more reliably obtained in the
three-dimensional shaped article 10.
[0192] Also, for example, adjusting the treatment conditions in the
curing step makes it possible to give the sacrificial layers 12 a
comparatively lower degree of polymerization even while giving the
substantive section 11 an adequately high degree of curing after
the end of the curing step. This results in making it possible to
more easily remove the sacrificial layers 12 in the sacrificial
layer removal step and making it possible to give the
three-dimensional shaped article 10 particularly excellent
productivity.
[0193] So doing is also preferable from the viewpoint of conserving
energy, because there is no need to increase more than necessary
the amount of energy rays to be irradiated.
[0194] In particular, where the content ratio of the polymerization
initiator in the substantive section-forming ink 11' is X.sub.1
[mass %] and the content ratio of the polymerization initiator in
the sacrificial layer-forming ink 12' is X.sub.2 [mass %], the
relationship 1.05.ltoreq.X.sub.1/X.sub.2.ltoreq.2.0 is preferably
satisfied; more preferably, the relationship
1.1.ltoreq.X.sub.1/X.sub.2.ltoreq.1.5 is satisfied.
[0195] This makes it possible for the substantive section-forming
ink 11' and the sacrificial layer-forming ink 12' to each be cured
at a more appropriate speed, causes the glossy outer appearance to
be even more reliably obtained in the three-dimensional shaped
article 10, and makes it possible to give the three-dimensional
shaped article 10 even more excellent productivity.
[0196] As a specific value for the content ratio of the
polymerization initiator in the substantive section-forming ink
11', 3.0 to 18 mass % is preferable; 5.0 to 15 mass % is even more
preferable.
[0197] This makes it possible to cure the substantive
section-forming ink 11' at a more appropriate speed of curing,
causes the glossy outer appearance to be more reliably obtained in
the three-dimensional shaped article 10, and makes it possible to
provide the three-dimensional shaped article 10 with particularly
excellent productivity.
[0198] The substantive section 11 that is formed by curing the
substantive section-forming ink 11' can also be given particularly
excellent mechanical strength and shape stability. As a result, the
three-dimensional shaped article 10 can be given particularly
excellent strength, durability, and reliability.
[0199] A preferred specific example of the blending ratio (an ink
composition, which excludes "other components" described below) of
the curable resin and polymerization initiator in the substantive
section-forming ink 11' shall be illustrated below, but it shall be
readily understood that the composition of the substantive
section-forming ink in the present invention is in no way limited
to what is described below.
[0200] [Blending Ratio Example]
[0201] 2-(2-vinyloxyethoxy) ethyl acrylate: 32 parts by mass
[0202] Polyether-based aliphatic urethane acrylate oligomer: 10
parts by mass
[0203] 2-hydroxy-3-phenoxypropylacrylate 13.75 parts by mass
[0204] Dipropyleneglycol diacrylate: 15 parts by mass
[0205] 4-hydroxybutylacrylate: 20 parts by mass
[0206] Bis(2,4,6-trimethylbenzoyl)phenylphoshine oxide: 5 parts by
mass
[0207] 2,4,6-trimethylbenzoyl diphenyl phosphone oxide: 4 parts by
mass
[0208] In a case of the above such formulation, the above such
effects are more prominently exhibited.
[0209] (Other Components)
[0210] In addition, the substantive section-forming ink 11' may
also comprise components other than those described above.
[0211] Examples of such components include a variety of coloring
agents such as a pigment or dye; a dispersing agent; a surfactant;
a sensitizer; a polymerization accelerator; a solvent; a
penetration enhancer; a wetting agent (humectant); a fixing agent;
an anti-fungal agent; a preservative; an antioxidant; an
ultraviolet ray absorption agent; a chelating agent; a pH adjusting
agent; a thickener; a filler; an aggregation inhibitor; an
anti-foaming agent; and the like.
[0212] In particular, when the substantive section-forming ink 11'
comprises a coloring agent, this makes it possible to obtain a
three-dimensional shaped article 10 that has been colored to a
color corresponding to the color of the coloring agent.
[0213] In particular, comprising a pigment as a coloring agent
makes it possible to give the substantive section-forming ink 11'
and the three-dimensional shaped article 10 favorable light
resistance. For the pigment, it would be possible to use an
inorganic pigment or an organic pigment.
[0214] Examples of inorganic pigments include: carbon blacks (C.I.
Pigment Black 7) such as furnace black, lamp black, acetylene black
and channel black; iron oxide, or titanium oxide; from which one
kind can be selected for use, or two or more kinds can be combined
for use.
[0215] Of these inorganic pigments, titanium oxide is preferable
because of the preferable white color exhibited thereby.
[0216] Examples of inorganic pigments include: an azo pigment such
as an insoluble azo pigment, a condensed azo pigment, azo lake, or
chelate azo pigment; a polycyclic pigment such as a phthalocyanine
pigment, a perylene or perynone pigment, an anthraquinone pigment,
a quinacridone pigment, a dioxane pigment, a thioindigo pigment, an
isoindolinone pigment, or a quinophthalone pigment; dye chelate
(for example, a basic dye chelate or an acidic dye chelate, or the
like); a color lake (a basic dye lake or an acidic dye lake); a
nitro pigment; a nitroso pigment; aniline black; or a daylight
fluorescent pigment; it would also be possible to use one species
selected from these or a combination of two or more species
selected from these.
[0217] More specifically, examples of carbon blacks that are used
as pigments for the color black include: No. 2300, No. 900, MCF88,
No. 33, No. 40, No. 45, No. 52, MA7, MA8, MA100, No. 2200B, and the
like (Mitsubishi Chemical); Raven 5750, Raven 5250, Raven 5000,
Raven 3500, Raven 1255, Raven 700, and the like (Carbon Columbia);
Rega1 400R, Rega1 330R, Rega1 660R, Mogul L, Monarch 700, Monarch
800, Monarch 880, Monarch 900, Monarch 1000, Monarch 1100, Monarch
1300, Monarch 1400, and the like (Cabot Japan); and Color Black
FW1, Color Black FW2, Color Black FW2V, Color Black FW18, Color
Black FW200, Color Black S150, Color Black S160, Color Black S170,
Printex 35, Printex U, Printex V, Printex 140U, Special Black 6,
Special Black 5, Special Black 4A, Special Black 4 (Degussa).
[0218] Examples of pigments for the color white include C.I.
Pigment White 6, 8, and 21.
[0219] Examples of pigments for the color yellow include C.I.
Pigment Yellow 1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 13, 14, 16, 17, 24,
34, 35, 37, 53, 55, 65, 73, 74, 75, 81, 83, 93, 94, 95, 97, 98, 99,
108, 109, 110, 113, 114, 117, 120, 124, 128, 129, 133, 138, 139,
147, 151, 153, 154, 167, 172, and 180.
[0220] Examples of pigments for the color magenta include C.I.
Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 14, 15, 16, 17,
18, 19, 21, 22, 23, 30, 31, 32, 37, 38, 40, 41, 42, 48 (Ca), 48
(Mn), 57 (Ca), 57:1, 88, 112, 114, 122, 123, 144, 146, 149, 150,
166, 168, 170, 171, 175, 176, 177, 178, 179, 184, 185, 187, 202,
209, 219, 224, and 245, or C.I. Pigment Violet 19, 23, 32, 33, 36,
38, 43, and 50.
[0221] Examples of pigments for the color cyan include C.I. Pigment
Blue 1, 2, 3, 15, 15:1, 15:2, 15:3, 15:34, 15:4, 16, 18, 22, 25,
60, 65, 66, and C.I. Vat Blue 4 and 60.
[0222] Examples of pigments other than those mentioned above
include C.I. Pigment Green 7 and 10, C.I. Pigment Brown 3, 5, 25,
and 26, and C.I. Pigment Orange 1, 2, 5, 7, 13, 14, 15, 16, 24, 34,
36, 38, 40, 43, and 63.
[0223] In a case where the substantive section-forming ink 11'
comprises a pigment, then the mean particle size of the pigment is
preferably 300 nm or smaller, more preferably 50 to 250 nm.
[0224] This makes it possible to give the substantive
section-forming ink 11' particularly excellent discharge stability
and to give the pigment in the substantive section-forming ink 11'
particularly excellent dispersion stability, and makes it possible
to form an image of more excellent image quality.
[0225] Examples of dyes include an acidic dye, a direct dye, a
reactive dye, or a basic dye; it would also be possible to use one
species selected from these or a combination of two or more species
selected from these.
[0226] Specific examples of dyes include C.I. Acid Yellow 17, 23,
42, 44, 79, and 142, C.I. Acid Red 52, 80, 82, 249, 254, and 289,
C.I. Acid Blue 9, 45, and 249, C.I. Acid Black 1, 2, 24, and 94,
C.I. Food Black 1 and 2, C.I. Direct Yellow 1, 12, 24, 33, 50, 55,
58, 86, 132, 142, 144, and 173, C.I. Direct Red 1, 4, 9, 80, 81,
225, and 227, C.I. Direct Blue 1, 2, 15, 71, 86, 87, 98, 165, 199,
and 202, C.I. Direct Black 19, 38, 51, 71, 154, 168, 171, and 195,
C.I. Reactive Red 14, 32, 55, 79, and 249, and C.I. Reactive Black
3, 4, and 35.
[0227] In a case where the substantive section-forming ink 11'
comprises a coloring agent, then the content ratio of the coloring
agent in the substantive section-forming ink 11' is preferably 1 to
20 mass %. This produces particularly excellent masking and color
reproducibility.
[0228] In particular, in a case where the substantive
section-forming ink 11' comprises titanium oxide as a coloring
agent, then the content ratio of the titanium oxide in the
substantive section-forming ink 11' is preferably 12 to 18 mass %,
more preferably 14 to 16 mass %. This produces particularly
excellent masking.
[0229] In a case where the substantive section-forming ink 11'
comprises a pigment, then when a dispersing agent is also included,
the dispersibility of the pigment can be further improved.
[0230] Though not particularly limited, examples of dispersing
agents include dispersing agents that are commonly used to prepare
pigment dispersions, such as polymeric dispersing agents.
[0231] Specific examples of polymeric dispersing agents include
those composed mainly of one or more species from among
polyoxyalkylene polyalkylene polyamine, vinyl-based polymers and
copolymers, acrylic polymers and copolymers, polyester, polyamide,
polyimide, polyurethane, amino-based polymers, silicon-containing
polymers, sulfur-containing polymers, fluorine-containing polymers,
and epoxy resins.
[0232] Examples of commercially available forms of polymeric
dispersing agents include Ajinomoto Fine-Techno's Ajisper series,
the Solsperse series (Solsperse 36000 and the like) available from
Noveon, BYK's Disperbyk series, and Kusumoto Chemicals' Disparlon
series.
[0233] When the substantive section-forming ink 11' comprises a
surfactant, the abrasion resistance of the three-dimensional shaped
article 10 can be further improved.
[0234] Though not particularly limited, examples of what can be
used as a surfactant include polyester-modified silicone or
polyether-modified silicone serving as a silicone-based surfactant;
of these, it is preferable to use polyether-modified
polydimethylsiloxane or polyester-modified
polydimethylsiloxane.
[0235] Specific examples of surfactants include BYK-347, BYK-348,
and BYK-UV 3500, 3510, 3530, and 3570 (which are trade names of
BYK).
[0236] The substantive section-forming ink 11' may also comprise a
solvent.
[0237] This makes it possible to suitably adjust the viscosity of
the substantive section-forming ink 11', and makes it possible to
give the substantive section-forming ink 11' particularly excellent
stability of discharge by inkjet format even when the substantive
section-forming ink 11' comprises high-viscosity components.
[0238] Examples of solvents include: (poly)alkylene glycol
monoalkyl ethers such as ethylene glycol monomethyl ether, ethylene
glycol monoethyl ether, propylene glycol monomethyl ether, and
propylene glycol monoethyl ether; acetic acid esters such as ethyl
acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, and
isobutyl acetate; aromatic hydrocarbons such as benzene, toluene,
and xylene; ketones such as methyl ethyl ketone, acetone, methyl
isobutyl ketone, ethyl-n-butyl ketone, diisopropyl ketone, and
acetylacetone; and alcohols such as ethanol, propanol, and butanol;
it would also be possible to use one species selected from these or
a combination of two or more species selected from these.
[0239] The viscosity of the substantive section-forming ink 11' is
preferably 10 to 30 mPas, more preferably 15 to 25 mPas.
[0240] This makes it possible to give the substantive
section-forming ink 11' particularly excellent stability of
discharge by inkjet. In the present specification, "viscosity"
refers to a value measured at 25.degree. C. using an E-type
viscometer (Visconic ELD made by Tokyo Keiki).
[0241] A plurality of kinds of substantive section-forming ink 11'
may be used in the manufacture of the three-dimensional shaped
article 10.
[0242] For example, a substantive section-forming ink 11' (color
ink) that comprises a coloring agent and a substantive
section-forming ink 11' (clear ink) that does not comprise a
coloring agent may both be used.
[0243] This makes it possible, for example, to use the substantive
section-forming ink 11' that comprises the coloring agent as a
substantive section-forming ink 11' applied to a region where the
color tone is affected in terms of the outer appearance of the
three-dimensional shaped article 10 and to use the substantive
section-forming ink 11' that does not comprise a coloring agent as
a substantive section-forming ink 11' applied to a region where the
color tone is not affected in terms of the outer appearance of the
three-dimensional shaped article 10, and is advantageous due in
part to reducing the costs of producing the three-dimensional
shaped article 10.
[0244] Also, a plurality of kinds of substantive section-forming
ink 11' may be used in combination so as to provide a region
(coating layer) formed using the substantive section-forming ink
11' that does not comprise a coloring agent on the outer surface of
a region formed using the substantive section-forming ink 11' that
does comprise a coloring agent, in the three-dimensional shaped
article 10 that is ultimately obtained.
[0245] This makes it possible to more suitably render the glossy
texture.
[0246] The substantive section 11 that comprises the coloring agent
(in particular, pigment) is more brittle and prone to scratches,
chipping, and the like than the substantive section 11 that does
not comprise the coloring agent, but providing the region (coating
layer) formed using the substantive section-forming ink 11' that
does not comprise the coloring agent makes it possible to
effectively prevent the occurrence of such problems.
[0247] Changes in the color tone of the three-dimensional shaped
article 10 can also be effectively prevented and suppressed even in
a case where long-term use of the three-dimensional shaped article
10 causes the surface to become worn.
[0248] Also, for example, a plurality of kinds of substantive
section-forming ink 11' that comprise coloring agents of different
compositions may be used.
[0249] This makes it possible to broaden the color reproduction
range that can be rendered, using these combinations of substantive
section-forming ink 11'.
[0250] In a case where a plurality of kinds of substantive
section-forming ink 11' are used, it is preferable to use at least
an indigo purple (cyan) substantive section-forming ink 11', a red
purple (magenta) substantive section-forming ink 11', and a yellow
substantive section-forming ink 11'.
[0251] This makes it possible to further broaden the color
reproduction range that can be rendered, using these combinations
of substantive section-forming ink 11'.
[0252] Combined use of a white substantive section-forming ink 11'
with substantive section-forming inks 11' of other colors also
produces the following effects.
[0253] Namely, the three-dimensional shaped article 10 that is
ultimately obtained can be endowed with a first region to which the
white substantive section-forming ink 11' is applied and a region
(second region) to which a substantive section-forming ink 11' of
that is colored (in particular, chromatic) a color other than white
is applied, provided on the outer surface side from the first
region. This makes it possible for the first region to which the
white substantive section-forming ink 11' is applied to exhibit
masking, and makes it possible to further raise the chroma of the
three-dimensional shaped article 10.
[0254] Also, the aforementioned effect where the glossy texture is
obtained and the effect where the chroma is increased act
synergistically together, making it possible to give the
three-dimensional shaped article 10 a particularly excellent
aesthetic appearance (aesthetic).
[0255] <Sacrificial Layer-Forming Ink>
[0256] The sacrificial layer-forming ink 12' comprises at least a
curable resin (curing component).
[0257] (Curable Resin)
[0258] Examples of the curable resin (curing component)
constituting the sacrificial layer-forming ink 12' include similar
ones to those curable resins (curing components) illustratively
exemplified as the constituent component of the substantive
section-forming ink 11'.
[0259] In particular, the curable resin (curing component)
constituting the sacrificial layer-forming ink 12' and the
aforementioned curable resin (curing component) constituting the
substantive section-forming ink 11' are preferably cured by the
same kind of energy ray.
[0260] This makes it possible to effectively prevent the
configuration of the apparatus for manufacturing a
three-dimensional shaped article from becoming complicated, and
makes it possible to give the three-dimensional shaped article 10
particularly excellent productivity. The surface shape of the
three-dimensional shaped article 10 can also be more reliably
controlled.
[0261] Of the variety of curing components, it is particularly
preferable for the sacrificial layer-forming ink 12' to comprise
2-(2-vinyloxyethoxy)ethyl(meth)acrylate.
[0262] This makes it possible to cure the sacrificial layer-forming
ink 12' at a more appropriate speed of curing, causes the glossy
outer appearance to be more reliably obtained in the
three-dimensional shaped article 10, and makes it possible to
provide the three-dimensional shaped article 10 with particularly
excellent productivity.
[0263] The sacrificial layers 12 that are formed by curing the
sacrificial layer-forming ink 12' can also be given particularly
excellent mechanical strength and stability of shape. As a result,
during the manufacture of the three-dimensional shaped article 10,
the sacrificial layer 12 of the lower layer (first layer) can more
suitably support the substantive section-forming ink 11' for
forming the upper layer (second layer). Therefore, unintended
deformation (in particular, sagging and the like) of the
substantive section 11 can be suitably prevented (the sacrificial
layer 12 of the first layer functions as a support material), and
the three-dimensional shaped article 10 that is ultimately obtained
can be given particularly excellent dimensional accuracy.
[0264] The sacrificial layer-forming ink 12' also preferably
comprises polyethylene glycol di(meth)acrylate, in addition to
2-(2-vinyloxyethoxy)ethyl(meth)acrylate.
[0265] This makes it possible to cure the sacrificial layer-forming
ink 12' at an even more appropriate speed of curing, causes the
glossy outer appearance to be more reliably obtained in the
three-dimensional shaped article 10, and makes it possible to
provide the three-dimensional shaped article 10 with particularly
excellent productivity.
[0266] The sacrificial layers 12 that are formed by curing the
sacrificial layer-forming ink 12' can also be given even more
excellent mechanical strength and stability of shape. As a result,
during the manufacture of the three-dimensional shaped article 10,
the sacrificial layer 12 of the lower layer (first layer) can even
more suitably support the substantive section-forming ink 11' for
forming the upper layer (second layer). Therefore, unintended
deformation (in particular, sagging and the like) of the
substantive section 11 can be even more suitably prevented (the
sacrificial layer 12 of the first layer functions as a support
material), and the three-dimensional shaped article 10 that is
ultimately obtained can be given even more excellent dimensional
accuracy.
[0267] When the sacrificial layer-forming ink 12' comprises
(meth)acryloylmorpholine, the following effects are obtained.
[0268] Namely, (meth)acryloylmorpholine is such that the solubility
in a variety of solvents is high in a state (polymer of
(meth)acryloylmorpholine in an incompletely cured state) where
curing is not complete even in a case where the curing reaction has
advanced. As such, the sacrificial layers 12 can be selectively,
reliably, and efficiently removed even while defects are being more
effectively prevented from occurring in the substantive section 11
in the aforementioned sacrificial layer removal step. As a result,
the three-dimensional shaped article 10 of the desired form can be
obtained at higher reliability and with favorable productivity.
[0269] When the sacrificial layer-forming ink 12' comprises one or
more species selected from the group consisting of ethoxylated
(3)trimethylolpropane triacrylate, tripropylene glycol diacrylate,
and dipropylene glycol diacrylate, then the viscoelasticity of the
sacrificial layers 12 is increased, and the glossy texture of the
substantive section 11 surface is more effectively formed.
[0270] In a case where the sacrificial layer-forming ink 12'
comprises 2-(2-vinyloxyethoxy)ethyl(meth)acrylate, then the content
ratio of 2-(2-vinyloxyethoxy)ethyl(meth)acrylate in the sacrificial
layer-forming ink 12' is preferably 20 to 50 mass %, more
preferably 25 to 45 mass %, even more preferably 30 to 40 mass %.
This causes the above such effects to be more prominently
exhibited.
[0271] In a case where the sacrificial layer-forming ink 12'
comprises polyethylene glycol di(meth)acrylate, then the content
ratio of polyethylene glycol di(meth)acrylate in the sacrificial
layer-forming ink 12' is preferably 40 to 70 mass %, more
preferably 35 to 65 mass %, even more preferably 30 to 60 mass %.
This causes the above such effects to be more prominently
exhibited.
[0272] The ratio ((X.sub.B/X.sub.A.times.100) of the content ratio
X.sub.B [mass %] of polyethylene glycol di(meth)acrylate with
respect to the content ratio X.sub.A [mass %] of
2-(2-vinyloxyethoxy)ethyl(meth)acrylate in the sacrificial
layer-forming ink 12' is preferably 120 to 180%, more preferably
130 to 170%, even more preferably 140 to 165%. This causes the
above such effects to be more prominently exhibited.
[0273] The content ratio of the curing component in the sacrificial
layer-forming ink 12' is preferably 83 to 98.5 mass %, more
preferably 87 to 95.4 mass %.
[0274] This makes it possible to endow the sacrificial layers 12
that are formed with particularly excellent shape stability, makes
it possible to more effectively prevent the underlying layers 1
from experiencing unintended deformation in a case where the layers
1 have been stacked during the manufacture of the three-dimensional
shaped article 10, and makes it possible to more suitably support
the upper layer 1. As a result, the three-dimensional shaped
article 10 that is ultimately obtained can be given particularly
excellent dimensional accuracy. It is also possible to give the
three-dimensional shaped article 10 particularly excellent
productivity.
[0275] (Polymerization Initiator)
[0276] The sacrificial layer-forming ink 12' preferably comprises a
polymerization initiator.
[0277] This makes it possible to appropriately increase the speed
of curing of the sacrificial layer-forming ink 12' during the
manufacture of the three-dimensional shaped article 10, and makes
it possible to give the three-dimensional shaped article 10
particularly excellent productivity.
[0278] This also makes it possible to endow the sacrificial layers
12 that are formed with particularly excellent shape stability,
makes it possible to more effectively prevent the underlying layers
1 from experiencing unintended deformation in a case where the
layers 1 have been stacked during the manufacture of the
three-dimensional shaped article 10, and makes it possible to more
suitably support the upper layer 1. As a result, the
three-dimensional shaped article 10 that is ultimately obtained can
be given particularly excellent dimensional accuracy.
[0279] Examples of the polymerization initiator constituting the
sacrificial layer-forming ink 12' are similar to the polymerization
initiators illustratively exemplified as a constituent component of
the substantive section-forming ink 11'.
[0280] In particular, it is preferable for the sacrificial
layer-forming ink 12' to comprise
bis(2,4,6-trimethylbenzoyl)-phenyl phosphineoxide and/or
2,4,6-trimethylbenzoyl-diphenyl-phosphineoxide as the
polymerization initiator.
[0281] Comprising such a polymerization initiator makes it possible
to cure the sacrificial layer-forming ink 12' at a more appropriate
curing speed, causes the glossy outer appearance to be more
reliably obtained in the three-dimensional shaped article 10, and
makes it possible to give the three-dimensional shaped article 10
particularly excellent productivity.
[0282] The sacrificial layers 12 that are formed by curing the
sacrificial layer-forming ink 12' can also be given particularly
excellent mechanical strength and stability of shape. As a result,
during the manufacture of the three-dimensional shaped article 10,
the sacrificial layer 12 of the lower layer (first layer) can more
suitably support the substantive section-forming ink 11' for
forming the upper layer (second layer). Therefore, unintended
deformation (in particular, sagging and the like) of the
substantive section 11 can be suitably prevented (the sacrificial
layer 12 of the first layer functions as a support material), and
the three-dimensional shaped article 10 that is ultimately obtained
can be given particularly excellent dimensional accuracy.
[0283] As a specific value for the content ratio of the
polymerization initiator in the sacrificial layer-forming ink 12',
1.5 to 17 mass % is preferable; 4.6 to 13 mass % is even more
preferable.
[0284] This makes it possible to cure the sacrificial layer-forming
ink 12' at a more appropriate speed of curing, causes the glossy
outer appearance to be more reliably obtained in the
three-dimensional shaped article 10, and makes it possible to
provide the three-dimensional shaped article 10 with particularly
excellent productivity.
[0285] The sacrificial layers 12 that are formed by curing the
sacrificial layer-forming ink 12' can also be given particularly
excellent mechanical strength and stability of shape. As a result,
during the manufacture of the three-dimensional shaped article 10,
the sacrificial layer 12 of the lower layer (first layer) can more
suitably support the substantive section-forming ink 11' for
forming the upper layer (second layer). Therefore, unintended
deformation (in particular, sagging and the like) of the
substantive section 11 can be suitably prevented (the sacrificial
layer 12 of the first layer functions as a support material), and
the three-dimensional shaped article 10 that is ultimately obtained
can be given particularly excellent dimensional accuracy.
[0286] A preferred specific example of the blending ratio (an ink
composition, which excludes "other components" described below) of
the curable resin and polymerization initiator in the sacrificial
layer-forming ink 12' shall be illustrated below, but it shall be
readily understood that the composition of the sacrificial
layer-forming ink in the present invention is in no way limited to
what is described below.
[0287] [Blending Ratio Example 1]
[0288] 2-(2-vinyloxyethoxy) ethyl acrylate: 36 parts by mass
[0289] Polyethylene glycol (400) diacrylate: 55.75 parts by
mass
[0290] Bis(2,4,6-trimethylbenzoyl)-phenyl phosphineoxide: 3 parts
by mass
[0291] 2,4,6-trimethylbenzoyl-diphenyl-phosphineoxide: 5 parts by
mass
[0292] In a case of the above such formulation, the above such
effects are more prominently exhibited.
[0293] (Other Components)
[0294] In addition, the sacrificial layer-forming ink 12' may also
comprise components other than those described above. Examples of
such components include a variety of coloring agents such as a
pigment or dye; a dispersing agent; a surfactant; a sensitizer; a
polymerization accelerator; a solvent; a penetration enhancer; a
wetting agent (humectant); a fixing agent; an anti-fungal agent; a
preservative; an antioxidant; an ultraviolet ray absorption agent;
a chelating agent; a pH adjusting agent; a thickener; a filler; an
aggregation inhibitor; an anti-foaming agent; and the like.
[0295] In particular, when the sacrificial layer-forming ink 12'
comprises a coloring agent, this improves the visibility of the
sacrificial layers 12, making it possible to more reliably prevent
at least a part of the sacrificial layers 12 from remaining in an
unintended manner in the three-dimensional shaped article 10 that
is ultimately obtained.
[0296] Examples of coloring agents constituting the sacrificial
layer-forming ink 12' are similar to the coloring agents
illustratively exemplified as a constituent component of the
substantive section-forming ink 11', but the coloring agent is
preferably a different color than the color (the color that is to
be visible in terms of the outer appearance of the
three-dimensional shaped article 10) of the substantive section 11,
which overlaps with the sacrificial layers 12 formed by the
sacrificial layer-forming ink 12' when observed from the normal
direction of the surface of the three-dimensional shaped article
10. This causes the above such effects to be more prominently
exhibited.
[0297] In a case where the sacrificial layer-forming ink 12'
comprises a pigment, then when a dispersing agent is also included,
the dispersibility of the pigment can be further improved. Examples
of the dispersing agent constituting the sacrificial layer-forming
ink 12' are similar to the dispersing agents illustratively
exemplified as a constituent component of the substantive
section-forming ink 11'.
[0298] The viscosity of the sacrificial layer-forming ink 12' is
preferably 10 to 30 mPas, more preferably 15 to 25 mPas.
[0299] This makes it possible to give the sacrificial layer-forming
ink 12' particularly excellent stability of discharge by
inkjet.
[0300] A plurality of kinds of sacrificial layer-forming ink 12'
may be used in the manufacture of the three-dimensional shaped
article 10.
[0301] For example, two or more kinds of sacrificial layer-forming
ink 12' that have mutually different viscoelasticities during
curing of the substantive section-forming ink 11' can be used.
[0302] This makes it possible for the three-dimensional shaped
article 10 that is ultimately obtained to have a plurality of
regions at which the degree of glossiness is different. As a
result, it becomes possible to render a more complex outer
appearance, and the three-dimensional shaped article 10 can be
given a particularly excellent aesthetic appearance (aesthetics),
luxuriousness, and the like.
[0303] It is also conceivable, for example, to use two or more
kinds of substantive section-forming ink 11' having each having a
different viscoelasticity during curing in order to obtain such
effects, but in such a case, there is the possibility that problems
such as when the physical properties at each of the sites of the
three-dimensional shaped article 10 that is ultimately obtained are
different in an unintended manner could occur; by contrast, in a
case where a plurality of kinds of sacrificial layer-forming ink
12' are used, it is possible to obtain the aforementioned effects
even while reliably preventing the occurrence of such problems.
[0304] The ink set of the present invention need only be provided
with at least one kind of substantive section-forming ink (first
ink) 11' and at least one kind of sacrificial layer-forming ink
(second ink) 12', but may also be provided with a third ink
different therefrom.
[0305] Examples of the third ink include a sacrificial
layer-forming ink not satisfying the aforementioned conditions.
Being provided with such a third ink makes it possible to endow the
three-dimensional shaped article 10 with a region exhibiting the
glossy texture and a region exhibiting a texture other than glossy.
As a result, it becomes possible to render a more complex outer
appearance, and the three-dimensional shaped article 10 can be
given a particularly excellent aesthetic appearance (aesthetics),
luxuriousness, and the like.
[0306] According to the ink set of the present invention as
described above, the three-dimensional shaped article having a
glossy texture can be manufactured stably and efficiently. Also,
the yield of the three-dimensional shaped article is improved and
therefore the present invention is also advantageous in terms of
reducing the costs of manufacturing the three-dimensional shaped
article.
[0307] <<Three-Dimensional Shaped Article>>
[0308] The three-dimensional shaped article of the present
invention can be manufactured using the method of manufacture,
apparatus for manufacturing a three-dimensional shaped article, and
ink set as described above. This makes it possible to provide a
three-dimensional shaped article having a glossy texture.
[0309] Use of the three-dimensional shaped article of the present
invention is not particularly limited, but examples include an
ornamental article or presented article such as a doll or figure, a
medical device such as an implant, and the like.
[0310] The three-dimensional shaped article of the present
invention may also be applied to prototypes, mass-produced goods,
and custom-made goods.
[0311] The three-dimensional shaped article of the present
invention may also be a model (for example, a model of (an
automobile, a motorcycle, a boat, an airplane, or another such
vehicle, a building, an animal, a plant, or another such living
thing, a stone or another such natural (non-living) object, a
variety of food products, and the like).
[0312] With a model, it is preferable to faithfully reproduce the
texture and the like possessed by the original, but with a
three-dimensional shaped article manufactured using a conventional
lamination method, it has not been possible to respond sufficiently
to such a need. By contrast, with the present invention, it is
possible to suitable render a glossiness which has conventionally
been especially difficult to render stably. As such, the effects of
the present invention are more prominently exhibited in a case
where the present invention is applied to a model.
[0313] A preferred embodiment of the present invention have been
described above, but the present invention is in no way limited
thereto.
[0314] For example, the embodiment described above centers on
describing a case where the substantive section-forming ink and the
sacrificial layer-forming ink are discharged by inkjet, but the
substantive section-forming ink and the sacrificial layer-forming
ink may be applied with another method (for example, another print
method).
[0315] In the method of manufacture of the present invention, a
pre-treatment step, an intermediate treatment step, and a
post-treatment step may be carried out as needed.
[0316] Examples of the pre-treatment step include a step for
cleaning the stage, and the like.
[0317] Examples of the post-treatment step include a washing step,
a shape adjustment step for deburring and the like, an additional
curing step for increasing the degree of curing of the curable
resin constituting the substantive section, and the like.
[0318] An additional example of the post-treatment step may have a
step for performing a mirror-finishing treatment (polishing
treatment) for increasing the specularity (glossiness) of the
three-dimensional shaped article. As described above, in the
present invention, when the substantive section-forming ink and the
sacrificial layer-forming ink satisfy a predetermined relationship
as regards viscoelasticity, this makes it possible to endow the
surface with a high degree of flatness; therefore, even in a case
where such a post-treatment is performed, the post-treatment can be
easily performed in a short period of time, and therefore the
three-dimensional shaped article can be given excellent
productivity. The effect from when the substantive section-forming
ink and the sacrificial layer-forming ink satisfy a predetermined
relationship as regards viscoelasticity and the effect from
performing the post-treatment step act synergistically together,
making it possible to obtain an excellent mirror-finished outer
appearance that could not conventionally be achieved, even were the
post-treatment step to be performed.
[0319] The present invention may also be applied to a powder
lamination method (namely, a method for obtaining a
three-dimensional shaped article in the form of a laminate having a
plurality of layers to which a cured section is provided, by
repeatedly carrying out a series of operations that are to use a
powder to form a layer, and apply a curable ink to a predetermined
site of the layer to form the cured section).
GENERAL INTERPRETATION OF TERMS
[0320] In understanding the scope of the present invention, the
term "comprising" and its derivatives, as used herein, are intended
to be open ended terms that specify the presence of the stated
features, elements, components, groups, integers, and/or steps, but
do not exclude the presence of other unstated features, elements,
components, groups, integers and/or steps. The foregoing also
applies to words having similar meanings such as the terms,
"including", "having" and their derivatives. Also, the terms
"part," "section," "portion," "member" or "element" when used in
the singular can have the dual meaning of a single part or a
plurality of parts. Finally, terms of degree such as
"substantially", "about" and "approximately" as used herein mean a
reasonable amount of deviation of the modified term such that the
end result is not significantly changed. For example, these terms
can be construed as including a deviation of at least .+-.5% of the
modified term if this deviation would not negate the meaning of the
word it modifies.
[0321] While only a selected embodiment has been chosen to
illustrate the present invention, it will be apparent to those
skilled in the art from this disclosure that various changes and
modifications can be made herein without departing from the scope
of the invention as defined in the appended claims. Furthermore,
the foregoing descriptions of the embodiment according to the
present invention are provided for illustration only, and not for
the purpose of limiting the invention as defined by the appended
claims and their equivalents.
* * * * *